This application claims the benefit of European Application No. 00402488.1, filed Sep. 8, 2000.
1. Field of the Invention
The present invention relates generally to optical waveguide fiber arrays, and particularly to a tool for positioning arrays of optical waveguide fiber.
2. Technical Background
Optical fiber array blocks are used to connect multiple optical waveguide fibers to optical devices, for example, optical switch fabrics. One approach to making optical fiber array blocks is to use a base plate with parallel grooves. Typically, these grooves are etched, machined or molded and the final position of the optical waveguide fibers is a function of the manufacturing tolerances involved in fabricating the grooved base plates. Each of these manufacturing technologies has difficulty in producing high precision optical waveguide fiber array blocks in large quantities.
The position of the optical waveguide fibers within the array is important because a small misalignment may lead to unacceptably large degradation of an optical signal routed through the optical fiber array block. Therefore the deviation of a single fiber from its desired position can render the entire fiber block unusable.
Furthermore, as optical technology progresses optical devices are increasing in complexity and decreasing in size requiring both more optical waveguide fibers to be attached to a single device and that the optical waveguide fibers be placed closer together.
There is a need to make optical fiber array blocks where the optical waveguide fibers have a small pitch and are positioned with great precision.
One aspect of the present invention is a method for making fiber arrays. The method includes the step of loading optical waveguide fibers into a positioner having a number of reference surfaces. The method further includes the step of applying adhesive to a planar substrate, thereby forming an adhesive coated surface. The method further includes the step of forming a number of virtual V-grooves with the adhesive coated substrate and the reference surfaces. The method further includes the steps of placing the optical waveguide fibers in the virtual V-grooves and coupling the optical waveguide fibers to the planar substrate.
In another aspect, the present invention includes a tool for positioning optical waveguide fibers on an adhesive coated substrate including a holder and a pressure source. The holder includes a chamber coupled to the pressure source and multiple recesses configured to position the optical waveguide fibers. Each recess includes a reference surface and is connected to the chamber by a passageway. The pressure source is configured to selectively increase and decrease the pressure in the chamber.
In another aspect, the present invention includes a tool for positioning optical waveguide fibers on an adhesive coated substrate to form an optical waveguide fiber array. The tool includes a pressure source configurable to provide either positive or negative pressure and a controller coupled to the pressure source. The controller configures the pressure source to provide either positive or negative pressure. The tool also includes a holder having multiple channels. Each of the channels includes a reference surface. The holder also includes a number of passageways connecting each of the channels to the pressure source. The tool further includes a positioner that positions said holder over the adhesive coated substrate, thereby forming a number of virtual V-grooves with the reference surfaces and the adhesive coated substrate.
In another aspect, the present invention includes a tool for positioning optical waveguide fibers on an adhesive coated substrate to form an optical waveguide fiber array. The tool includes a pressure source configurable to provide either positive or negative pressure and a controller coupled to the pressure source. The controller configures the pressure source to provide either positive or negative pressure. The tool also includes a holder having multiple channels. Each of the channels includes a reference surface. The holder also includes a number of passageways connecting each of the channels to the pressure source. The tool further includes a positioner that brings the adhesive coated substrate into close proximity to the holder, thereby forming a number of virtual V-grooves with the reference surfaces and the adhesive coated substrate.
An advantage of the present invention is that high precision optical waveguide fiber arrays may be made without the need for high precision grooved substrates.
Another advantage of the present invention is that it reduces the costs of precision optical waveguide fiber array blocks.
Another advantage of the present invention is that it optical fiber arrays may be made with out either photolithography or etching.
Another advantage of the present invention is that it is easily adaptable into an automated assembly process.
Another advantage of the present invention is that it does not require the use of a vision system to position the optical fibers to form an array.
Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the invention, and together with the description serve to explain the principles and operation of the invention.